Table of Contents
EPA Water Disinfection Project
The Need for Clean WaterMany rural parts of developing regions around the world lack access to safe drinking water. Water that is contaminated with pathogens and viruses that are harmful to the human body is often the only option the people of these regions have for drinking water.
The World Health Organization stated in a report entitled, Water for Life, that diarrhoeal diseases claim the lives of 5,000 young children throughout the world everyday. The lack of clean drinking water throughout the world can also cause social instability if not death. The United Nations has also expressed concern through the Millennium Development Goals which are eight goals that address global problems and are aimed to be achieved by 2015. Some of these goals are eradicating hunger and poverty, achieving universal primary education, and reducing child mortality.
These goals become more reachable by providing clean water through a safe, clean, and inexpensive method.
SponsorshipA grant awarded by the Environmental Protection Agency will provide funding for the research and development of a solar water pasteurizer. The grant is part of the EPA's P3: People, Prosperity and the Planet Student Design Competition for Sustainability in which students devise various methods and products to address social, economic, and global concerns. The grants through the competition are awarded in two phases.
The team was awarded $10,000 as part of a Phase I grant to devise a working prototype of a solar pasteurizer. All Phase I teams compete for Phase II funding towards the end of the project duration which is set for $75,000.
More information on the P3 competition can be found here.
CustomersPeople of third world regions who lack access to clean, safe drinking water are the customers whose needs are to be met. Because there was no effective way to communicate between the customers and the design team on a global scale, Venezuela was targeted as a primary customer. Venezuela was chosen because the team had faculty members who had established points of contact with local Venezuelan non-governmental organizations and churches who worked closely with poorer sections of the country.
Mission StatementThe project mission is to design, construct, and test a working prototype of water pasteurizer that utilizes solar energy.
Solar Pasteurizer with Integral Heat Exchanger (SPIHX)
What is Pasteurization?Pasteurization is a method in which heat is used to kill bacteria, pathogens, or viruses. It is a function of time and temperature. The graph below shows this time-temperature relationship when pasteurizing water in what is called the safety zone curve.
Pasteurization is ensured if the safety zone is reached. For example if 68 deg. C. is maintained for at least 15 minutes then pasteurization has occurred and the water is drinkable.
How the SPIHX Works
The pasteurizer itself is made up of three sheets of aluminum that is enclosed in a plywood enclosure. The three sheets are assembled together such that two channels are created for water to flow through.
Incoming water travels through the top channel. The top aluminum sheet is painted with a selective coating which enhances solar absorptivity while retarding emissivity.
Once pasteurized, the thermostat valve opens and the water then flows through the bottom channel. The middle aluminum sheet facilitates heat exchange between the hot, outgoing pasteurized water and cold, incoming contaminated water.
The valve will remain closed until pasteurization levels have been reached. Once open, the valve will remain open as water will continuously pasteurize and flow making the SPIHX a faster means of obtaining potable water as opposed to a batch pasteurization process.
The image below outlines the steps in which the water flows through the SPIHX.
(1) Water is poured into the inlet bucket through a funnel fitted with a filter to separate sediments. (2) As water travels through the top channel solar flux warms it up. (3) The thermostat valve opens once pasteurization levels have been reached. (4) The pasteurized water flows through the bottom channel allowing new incoming water in the top channel to recover heat. (5) After the heat exchange process water flows into an outlet bucket.
The SPIHX Team
|Student Team Member||Team Role|
|Sang Lee||Project Managerfirstname.lastname@example.org|
|Elaine Aiken||Lead Engineeremail@example.com|
|Drazen Hadzialic||Lead Test Engineerfirstname.lastname@example.org|
|Nathan La Croix||Test Engineeremail@example.com|
|Alexander Kinlock||Material & Fabrication Analysisfirstname.lastname@example.org|
|Sulen Gonc||Material & Life Cycle Analysisemail@example.com|
|Faculty Member||Team Role|
|Dr. Robert Stevens||Team Guide / Customerfirstname.lastname@example.org|
|Dr. Andres Carrano||Faculty Consultantemail@example.com|
|Dr. Brian Thorn||Faculty Consultantfirstname.lastname@example.org|
|Dr. Margaret Bailey||Faculty Consultantemail@example.com|
The following files are arranged in accordance with the M.E.R.I.T. (Multidisciplinary Engineering Design Program at RIT) design process.
- Planning - The scope, mission statement, and goals of the project are defined and milestones are set through project schedules.
- Needs Assessment - Customers are interviewed and the needs are discussed among team members and then finalized with the customer. Engineering specifications are set based on the customer needs.
- Concept Development - Different ideas and methods are pitched among team members to achieve project goals and meet customer needs and engineering specifications.
- Concept Selection - Concept(s) that are most functional and practical are selected.
- Detail Design - Students along with aid from faculty apply engineering knowledge to finalize a design for a chosen concept.
- Function and Performance Review - Once built, the prototype is tested to see if it performs as per design and if all engineering specifications are met.
- Project Review - An overview of the project is presented addressing areas such as background, project schedules and milestones, budget, and performance of the final product.
- One Page Project Summary (PDF)
- House of Quality (EXCEL)
- Subfunction Diagram (PDF)
- Subfunctions Explained (PDF)
- Concept Selection Matrix (PDF)
ModelingNote: The models are constantly used by the team to better the design. The uploaded versions here may not reflect the final dimensions or specifications of the prototype.
Weather data from Puerto Rico was used because data from Venezuela was unobtainable. The latitude and climate is relatively close to that of Venezuela.
DrawingsThe following are zipped files containing drawings created through SolidWorks. Click on the link, save, and add in '.zip' at the end of the file name, and then unzip to view the drawings in SolidWorks.
- Pasteurizer Assembly (Rev. B)
- Enclosure Assembly (Rev. E)
- Valve Housing Assembly (Rev. C)
- Heat Exchanger Tubing (Rev. C)
- Inlet Water Table (Rev. B)
- Fabrication Tools (superceded - not needed)
- Bill of Materials (PDF)
Function and Performance Review
- Setup Usability Test Method (PDF)
- Preventive Maintenance Test Method (PDF)
- SPIHX Test Method (WORD)
- Function and Performance Summary
Poster & Technical Paper
- MSD II Project Review Presentation (PowerPoint)
- PHASE I Proposal (PDF)
- PHASE I Proposal with Supplement with Contacts (WORD)
- Poster (JPEG)
- Supplemental Poster (JPEG)
- EPA Final Report (PDF)
- EPA Phase II Proposal (PDF)
- RJS MS Thesis (PDF)
- Design and Analysis of Pasteurizer Concept Paper (PDF)
- Integral Heat Exchanger Paper (PDF)
- DOE Solar Pasteurizer Report (PDF)
- WHO Water for Life (PDF)